I have asymmetrical shoulder alignment, so one arm is effectively longer than the other one by a quarter inch (?) or so. I'm a Clydesdale and I can get around 3 hours of riding in before my shoulder blade area muscles hurt on one side of my body. To help shore up the gap, I added some gel pads to one side of my drops in a couple of places, which seems to have made an improvement but the pain still makes itself known in the middle of my long rides. I look forward to hearing your ideas! Thanks in advance.
John in DFW, TX